CURRENT STUDIES OF LIPOSOME MURAMYL TRIPEPTIDE (CGP 19835A LIPID) THERAPY FOR METASTASIS IN SPONTANEOUS TUMORS - A PROGRESS REVIEW

Targeted delivery of macrophage activating agents is an attractive app roach to treat micrometastatic disease. Liposome-encapsulated muramyl tripeptide phosphatidylethanolamine (L-MTP-PE) is a potent activator o f monocytes/macrophages in humans, mice, and dogs. We have conducted c linical trials in dogs with malignant and highly metastatic spontaneou s tumors. Presented are results of our trials evaluating L-MTP-PE in c ombination with surgery and chemotherapy in dogs with spontaneous oste osarcoma and hemangiosarcoma, particularly relevant malignancies havin g many similarities to human cancer. Osteosarcoma dogs received chemot herapy following surgery (cisplatin q 28 days x 4). At completion of c hemotherapy, dogs were randomized to receive L-MTP-PE or placebo. The L-MTP-PE group had a significantly longer median survival time compare d to the placebo group (p < 0.021). Dogs with splenic hemangiosarcoma received combination chemotherapy following surgery (doxorubicin and c yclophosphamide q 21 days x 4). At the first chemotherapy, dogs were r andomized to receive L-MTP-PE or placebo. The L-MTP-PE group had a sig nificantly longer median survival time compared to the placebo group ( p < 0.03). These studies show that L-MTP-PE is an effective agent for treatment of metastasis and can be safely administered in combination with chemotherapy.